Инд. авторы:	Doucet L.S., Mattielli N., Ionov D.A., Debouge W., Golovin A.V.
Заглавие:	Zn isotopic heterogeneity in the mantle: A melting control?
Библ. ссылка:	Doucet L.S., Mattielli N., Ionov D.A., Debouge W., Golovin A.V. Zn isotopic heterogeneity in the mantle: A melting control? // Earth and Planetary Science Letters. - 2016. - Vol.451. - P.232-240. - ISSN 0012-821X. - EISSN 1385-013X.
Внешние системы:	DOI: 10.1016/j.epsl.2016.06.040; SCOPUS: 2-s2.0-84990041241; WoS: 000382595500023;
Реферат:	eng: We present new Zn elemental and isotope data on seventeen fertile and refractory mantle peridotite xenoliths. Eleven fertile peridotites are garnet and spinel lherzolites from Vitim and Tariat (Siberia and Mongolia) and represent some of the most pristine fertile peridotites available. Six refractory peridotites are spinel harzburgites from the Udachnaya kimberlite (Siberian craton) that are nearly pristine residues of high-degree polybaric melting at high pressure (7–4 GPa). Geochemical data suggest that Zn isotopic compositions in the peridotites have not been affected by post-melting processes such as metasomatism, contamination by the host-magmas or alteration. The fertile peridotites have uniform Zn concentrations (59±2 ppm) and Zn isotopic compositions with δ66Zn (relative to JMC-Lyon-03-0749l) = +0.30 ± 0.03‰ consistent with the Bulk Silicate Earth estimates of δ66Zn = +0.28 ± 0.05‰ (Chen et al., 2013). The refractory peridotites have Zn concentrations ranging from 30 to 48 ppm and δ66Zn from +0.10±0.01‰ to +0.18±0.01‰ with an average of +0.14±0.03‰. Our data suggest that the lithospheric mantle has a heterogeneous Zn isotopic composition. Modeling of Zn isotope partitioning during partial melting of fertile mantle suggests that high degrees of melt extraction (>30%) may significantly fractionate Zn isotopes (up to 0.16‰) and that during mantle melting, Zn concentrations and isotopic compositions are mainly controlled by the stability of clinopyroxene and garnet within the melting residue. Because the stability of clinopyroxene and garnet is mainly pressure dependent we suggest that both the depth and the degrees of melt extraction may control Zn isotope fractionation during mantle melting. © 2016 Elsevier B.V.
Ключевые слова:	Stable isotopes; Peridotite xenoliths; Partial melting; Lithospheric mantle; Isotopic composition; Isotope fractionation; Silicates; Refractory materials; Melting; Zinc; Garnets; Extraction; zinc isotopic composition; peridotite xenolith; partial melting; non-traditional stable isotopes; lithospheric mantle; isotope fractionation; Isotopes;
Издано:	2016
Физ. характеристика:	с.232-240